DE3344469A1 - Drilling aids - Google Patents

Abstract

The invention relates to the use of specific polymers as aids for drilling muds.

Description

Tools for drilling

The invention relates to the use of special polymers as Aids for borehole flushing.

It is known as a drilling fluid for deep oil and natural gas wells e.g. to use aqueous clay suspensions.

The properties of such drilling muds can, however, be reduced in the case of deep boreholes become unstable at high temperatures or when encountering saline waters, whereby there is agglomeration of clay (bentonite), associated with deterioration the dishwashing properties. To stabilize such drilling mud, these Additives added, e.g. lignosulfonates, cellulose ethers such as carboxymethyl cellulose and polymers of acrylic acid and acrylamide (e.g. G.R. Gray et al., Composition and Properties of Oil well drilling Fluides, Gulf Publishing Company, 1979, pp. 164-177; U.S. Patent 4,036,660).

However, such carboxyl group-containing polymers are opposed sensitive to high salt concentrations, especially alkaline earth ions. Polysaccharide derivatives can especially degraded by exposure to higher temperatures and thus lose their effectiveness.

The addition of organic compounds to borehole flushing agents should on the one hand Improve the flow properties of the drilling mud, i.e. the viscosity of the drilling fluid and on the other hand prevent the release of water from the sludge. The above The compounds mentioned can therefore generally only be used in combinations with one another can be used, as each of them does not meet all requirements.

It has now been found that polymers containing aromatic sulfonic acid groups or contain their salt form, combine both effects.

The invention therefore relates to the use of polymers consisting of polymeric methylene chains with aromatic sulfonic acid groups of the formulas (I) and (II) in which R stands for phenylene or naphthylene optionally substituted with halogen such as chlorine and bromo C1 -C 4 -alkyl and sulfonic groups, R1 for hydrogen, C1-C10-alkyl, which can optionally be substituted with OH groups, 3 R2 for hydrogen, - NH2, -NR3 where R stands for H, C1-C4 -alkyl and M # stands for an alkali ion such as Li, Na, K +, 1/2 alkaline earth metal ion such as Mg² +, Ca² +, Ba² + or an amine salt such as 3 NR4 #, exist as an aid for borehole flushing.

The polymers which can be used according to the invention generally have mean molecular weights which are greater than 5000, preferably molecular weights from 20,000 -500,000.

The polymers which can be used according to the invention carry aromatic sulfonic acid groups. These sulfonic acid groups can be used as free acid groups -SO3H or as salts -SO3 M exist. You can use amide bonds (formula I) or imide bonds (formula II) be bound to the polymer.

The preparation of polymers which can be used according to the invention can e.g. by converting maleic anhydride (co) polymers or maleic acid ester (co) polymers for example with monoaminosulfonic acids. For example, from copolymers of ethylene and styrene with maleic anhydride or maleic acid (semi) esters Reaction with monomer sulfonic acids for the use according to the invention is preferred suitable products can be obtained.

The production of maleic anhydride or maleic acid half-ester (co) polymers can be carried out by known methods, for example by copolymerization of maleic anhydride or the maleic acid half-ester in solvents or by subsequent esterification the copolymers to form half-esters or diesters, such as in Houben-Weyl, methods der Organic Chemie, Volume XIV, 1, Georg Thieme Verlag, Stuttgart 1961, described.

Both polymers of maleic anhydride or

the (half) ester as well as copolymers of maleic anhydride or the (half) ester with other vinyl compounds such as vinyl acetate, styrene, isobutylene, Vinyl ether, ethylene or propylene, preferably with ethylene, propylene, isobutylene and styrene can be used.

Of the anhydride or half-ester groups, preference is given to the (co) polymers up to 90% have been converted with aromatic aminosulfonic acids.

The polymers according to the invention can optionally contain up to 50% Contain ester or carboxyl groups.

The polymers which can be used according to the invention contain sulfonic acid groups. These are preferably in the form of their water-soluble salts, e.g. as alkali or amine or. Ammonium salts.

The implementation of (co) polymers with aminosulfonic acids or their salts can in organic solvents or in an aqueous medium, preferably at temperatures from 20 to 1000C. Higher temperatures up to 200 "C are then preferred, if you want to get predominantly imide structures.

As the aromatic aminosulfonic acid, for example, sulfanilic acid is preferred or monoaminonaphthalene mono- or disulfonic acids are suitable.

Example 1 In a 2 liter stirred flask with internal thermometer and dropping funnel are 126 parts by weight of an alternating copolymer of ethylene and maleic anhydride with an average molecular weight of 100,000 dissolved in 800 parts by weight of acetone. Separately a concentrated aqueous solution of sulfanilic acid K salt is prepared by adding to a suspension of 173 parts by weight of sulfanilic acid, 300 parts by weight of water introduces 69 parts by weight of anhydrous potassium carbonate in portions at 50 ° C. with stirring. The resulting 500C warm solution becomes the same within 60 minutes The solution of the ethylene-maleic anhydride copolymer in acetone, heated to 500C, was added dropwise. The mixture is subsequently stirred at 50 ° C. for 2 hours.

The lumpy, slightly greasy dropout will be after peeling off the protruding Solvent stirred for 30 minutes with 1000 parts by weight of acetone at 250C and at 600C dried. After grinding in a hammer mill and drying again 600C, 305 parts by weight of a granular product are obtained. After 48 hours of dialysis in water the product had a sulfur content of 8.1%.

Example 2 According to Example 1, 202 parts by weight of an alternating Copolymer of styrene and maleic anhydride with an average molecular weight of 70,000 dissolved in 1,600 parts by weight of acetone. After drying and grinding 382 parts by weight of reaction product are obtained.

Example 3 According to Example 1, 140 parts by weight of an alternating Copolymer of propylene and maleic anhydride with an average molecular weight of 50,000 dissolved in 2000 parts by weight of acetone and reacted. 340 parts by weight are obtained of dried reaction product.

Example 4 In a 3 l stirred vessel with an internal thermometer, 195 Parts by weight of sulfanilic acid sodium salt at 90 ° C. with stirring in 2000 parts by weight of water solved. In the course of 15 minutes, 126 portions are added to the clear solution Parts by weight of an alternating copolymer of ethylene and maleic anhydride with an average molecular weight of 100,000. After the addition has ended, the mixture is stirred further 8 hours at 900C. A homogeneous solution with a solids content of 13.6%. Part of the solution is dialyzed against water for 48 hours and the part in the dialysis tube remaining solution concentrated to dryness. The sulfur analysis gives one Value of 6.4%.

Example 5 In a 6 l autoclave with anchor stirrer, 3150 parts by weight Submitted distilled water and 692 parts by weight of sulfanilic acid and stirring (n = 100 rpm) 700C heated. Be within 30 minutes added a little at a time, 277 parts by weight of anhydrous potassium carbonate. After 10 Minutes at 700C and a speed of 100 rpm. was stirred, one carries within of 30 minutes with further stirring 504 parts by weight of an alternating copolymer from ethylene and maleic anhydride with an average molecular weight of 100,000. The autoclave is then closed, evacuated and removed to remove oxygen residues Purged 3 times with 2 bar nitrogen.

The mixture is heated to 90 ° C. for 3 hours and to 18 ° C. for 2 hours, while stirring. After cooling, 4420 parts by weight of a solution with a solids content are obtained of 28.5% by weight.

The IR spectrum of the isolated solid indicates the one formed Imide structure -hin.

Example 6 In 1000 g of NaCl-saturated water, -42 g of attapulgite, 42 g Wyoming bentonite and 84 g inert clay are stirred in. The resulting sludge is sheared for 10 minutes at 4000 rpm with an Ultra-Thurrax stirrer and then 16 Left for hours.

The approach is divided into parts A and B. Part A becomes 1% Water, 1% of the product according to Example 1, was added to part B and the mixture was stirred for 10 minutes.

Then the apparent viscosity, the yield point and the 30 min-API water loss according to API-Standard RP 13 B measured.

Both slurries are then placed in sealed steel bombs 16 Aged hours at 1400C with movement, re-agitated and the data again certainly. The following values are found: Sample A Sample B Measured value before aging after aging before aging after aging apparent 49 70 28.5 16 viscosity (cP) yield point 345 288 34 38 (dyn / cm2) Water loss 112 155 15 15 (ml) Example 7 A Sludge prepared according to Example 6, with 12 g together with the inert clay CaSO4 can be added as plaster of paris.

The experiment is then continued as in Example 6.

The following data are determined: Sample A sample B measured value before aging after aging before aging after aging apparent 114.5 135 18.5 11.5 Viscosity (cP) yield point 850 920 4.8 14.4 (dyn / cm2) water loss 151 185 12 14 (ml) The products according to the invention show a thinning effect for improvement the viscosity of the drilling fluid with a fluid loss effect to prevent a Water loss of the drilling mud and are particularly with high stabilities of the Drilling agent effective, as the following table shows: Product Thinner Fluid Loss (required addition in% by weight) product according to the example 0.1-0.5% 2-4% game 1 Chromium lignosulfonate approx. 1% lower effect, low molecular weight approx. 2% lower Effect polyacrylic acids or their salts carboxymethyl - no effect 2 - 4% cellulose Copolymer of no effect 2 - 4% (acrylamide, AMPS, methyl vinyl acetamide) commercial product

Claims (2)

Claims 1) Use of polymers consisting of polymeric methylene chains with aromatic sulfonic acid groups of the formulas (I) and (II) in which R stands for phenylene or naphthylene optionally substituted by halogen, C1-C4-alkyl and sulfonic groups, R1 for hydrogen, C1-C10-alkyl, which may optionally be substituted by OH groups, R2 for hydrogen, -NH2, -NR23 where R2 stands for H, C1-C4-alkyl and MS stands for an alkali ion such as Li +, Na +, K +, 1/2 alkaline earth metal ion such as Mg2 + Ca2 + Br 2+ or an amine salt such as NR43 #, exist as an aid for borehole flushing. 2) Use of polymers according to claim 1, characterized in that that the polymers have average molecular weights greater than 5000.